Simulations of ion beam loss in rf linacs with emphasis on tails of particle distributions

We present a new approach for beam loss calculations that places emphasis on the tails of the particle distributions. This scheme is used for simulating the SARAF proton/deuteron accelerator, a 176 MHz RF linac complex consisting of a 4-rod RFQ and 44 SC half wave resonator (HWR) cavities designed to operate in CW mode at 4 mA beam current. We discuss our scheme for highlighting the tails of the particle bunches generated by the RFQ. Simulation of the RFQ and RF linac with the tail emphasis technique allows us to increase beam loss statistics by more than an order of magnitude. Error analysis studies now become more feasible and provide a realistic assessment of anticipated beam loss. The technique is also useful for linac tune and optimization with a beam containing the full tail profile but with less CPU time required.